Prevention of Hypercholesterolemic Atherosclerosis by Garlic, an Antixoidant

Curcumin and its nano-formulations combined with exercise: From molecular mechanisms to clinic

Curcumin is a strong substance derived from turmeric, a popular spice, renowned for its antioxidant and anti-inflammatory abilities. The study delved deeply into a thorough examination of various sources to evaluate the impact of both regular curcumin and nano-formulated curcumin on elements that impact physical performance, including muscular strain, discomfort, swelling, and oxidative tension. While engaging in exercise, the body experiences a rise in reactive oxygen species and inflammation. As a result, it is important to ensure a proper balance between internal and external sources of antioxidants to maintain stability in the skeletal muscle. Without this balance, there is a risk of muscle soreness, damage, and ultimately, a decline in exercise performance. Curcumin possesses the ability to enhance physical performance and reduce the symptoms of muscle fatigue and injury by virtue of its antioxidative and anti-inflammatory properties. Including curcumin supplements appears to have advantageous effects on various aspects of exercise, such as enhancing performance, assisting with recovery, lessening muscle damage and discomfort, and lowering levels of inflammation and oxidative stress. However, a thorough assessment is necessary to precisely gauge the healing advantages of curcumin in enhancing exercise ability and reducing recovery time.

Current Status of Primary, Secondary, and Tertiary Prevention of Coronary Artery Disease

Fifty percent of all death from cardiovascular diseases is due to coronary artery disease (CAD). This is avoidable if early identification is made. Preventive health care has a major role in the fight against CAD. Atherosclerosis and atherosclerotic plaque rupture are involved in the development of CAD. Modifiable risk factors for CAD are dyslipidemia, diabetes, hypertension, cigarette smoking, obesity, chronic renal disease, chronic infection, high C-reactive protein, and hyperhomocysteinemia. CAD can be prevented by modification of risk factors. This paper defines the primary, secondary, and tertiary prevention of CAD. It discusses the mechanism of risk factor-induced atherosclerosis. This paper describes the CAD risk score and its use in the selection of individuals for primary prevention of CAD. Guidelines for primary, secondary, and tertiary prevention of CAD have been described. Modification of risk factors and use of guidelines for prevention of CAD would prevent, regress, and slow down the progression of CAD, improve the quality of life of patient, and reduce the health care cost.

Canagliflozin ameliorates aortic and hepatic dysfunction in dietary-induced hypercholesterolemia in the rabbit

AIMS

Canagliflozin is an antidiabetic agent which lowers blood glucose levels by inhibiting the glucose reabsorption machinery in the proximal tubules. There have not been conducted any study on its direct impact on hypercholesterolemia and associated vascular disorders independently of blood glucose lowering activity.

MATERIALS AND METHODS

Rabbits were arranged in 3 groups: Group 1 (Control): regular rabbit chow; Group 2 (HCD): 1% cholesterol-enriched chow was given to rabbits for 4 weeks; Group 3 (HCD-CANA): 1% cholesterol-enriched chow was fed to rabbits concurrently with canagliflozin (10 mg/kg/day, orally) for 4 weeks. At the end of experiment, blood and tissue samples were obtained for biochemical, histological, immunohistochemical, and vascular reactivity assessment.

KEY FINDINGS

When statistically compared to Control (P < 0.05), HCD showed a significant increase in the serum triglycerides, low-density lipoprotein, total cholesterol, C-reactive protein, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. Furthermore, a significant decrease was seen in both liver and aortic levels of glutathione peroxidase and superoxide dismutase concurrently with a significant elevation in malondialdehyde levels. Aortic levels of nitrate/nitrite ratio were significantly elevated. Acetylcholine-induced relaxation was impaired as the E_max decreased significantly in aortae. Moreover, a significant increase was seen in the level of aortic intima/media ratio. Canagliflozin treatment significantly improved vascular function, lipid profile and inflammation and reduced liver injury.

SIGNIFICANCE

Our data suggest that SGLT-2 inhibition via canagliflozin not only possesses an antihyperglycemic activity, but also improves hypercholesterolemia, vascular and liver function in dietary-induced hypercholesterolemia in the rabbit.

AGE-RAGE Axis in the Pathophysiology of Chronic Lower Limb Ischemia and a Novel Strategy for Its Treatment

This review focuses on the role of advanced glycation end products (AGEs) and its cell receptor (RAGE) and soluble receptor (sRAGE) in the pathogenesis of chronic lower limb ischemia (CLLI) and its treatment. CLLI is associated with atherosclerosis in lower limb arteries. AGE-RAGE axis which comprises of AGE, RAGE, and sRAGE has been implicated in atherosclerosis and restenosis. It may be involved in atherosclerosis of lower limb resulting in CLLI. Serum and tissue levels of AGE, and expression of RAGE are elevated, and the serum levels of sRAGE are decreased in CLLI. It is known that AGE, and AGE-RAGE interaction increase the generation of various atherogenic factors including reactive oxygen species, nuclear factor-kappa B, cell adhesion molecules, cytokines, monocyte chemoattractant protein-1, granulocyte macrophage-colony stimulating factor, and growth factors. sRAGE acts as antiatherogenic factor because it reduces the generation of AGE-RAGE-induced atherogenic factors. Treatment of CLLI should be targeted at lowering AGE levels through reduction of dietary intake of AGE, prevention of AGE formation and degradation of AGE, suppression of RAGE expression, blockade of AGE-RAGE binding, elevation of sRAGE by upregulating sRAGE expression, and exogenous administration of sRAGE, and use of antioxidants. In conclusion, AGE-RAGE stress defined as a shift in the balance between stressors (AGE, RAGE) and antistressor (sRAGE) in favor of stressors, initiates the development of atherosclerosis resulting in CLLI. Treatment modalities would include reduction of AGE levels and RAGE expression, RAGE blocker, elevation of sRAGE, and antioxidants for prevention, regression, and slowing of progression of CLLI.

Curcumin - A Novel Therapeutic Agent in the Prevention of Colorectal Cancer

Background:

Colorectal cancer is the third important cause of cancer-associated deaths across the world. Hence, there is an urgent need for understanding the complete mechanism associated with colorectal cancer, which in turn can be utilized toward early detection as well as the treatment of colorectal cancer in humans. Though colorectal cancer is a complex process and chemotherapy is the first step toward the treatment of colorectal cancer, recently several studies suggested that dietary phytochemicals may also aid significantly in reducing colorectal cancer risk in human. However, only few phytochemicals, specifically curcumin derived from the rhizomes of Curcuma longa, have better chemotherapeutic property, which might be because of its ability to regulate the activity of key factors associated with the initiation, promotion, as well as progression of tumors.

Objectives:

In the present review, the authors made an attempt to summarize the physiochemical properties of curcumin, which in turn prevent colorectal cancer via regulating numerous cell signaling as well as genetic pathways.

Conclusions:

Accumulated evidence suggested that curcumin suppresses tumour/colon cancer in various ways, (a) restricting cell cycle progression, or stimulating apoptosis, (b) restricting angiogenesis, anti-apoptotic proteins expression, cell survival signaling pathways & their cross-communication and (c) regulating immune responses. The information discussed in the present review will be useful in the drug discovery process as well as the treatment and prevention of colorectal cancer in humans.

Cinnamaldehyde exerts vasculoprotective effects in hypercholestrolemic rabbits

The effects of cinnamaldehyde (CIN), a commonly consumed food flavor, against high-cholesterol diet (HCD)-induced vascular damage in rabbits were evaluated. Male New Zealand rabbits (n = 24) were allocated to four groups at random: control, fed with standard rabbit chow; CIN, fed with standard diet and administered CIN; HCD, fed with 1% cholesterol-enriched diet; and HCD-CIN, fed with HCD and treated with CIN. CIN was orally given at a dose of (10 mg/kg/day) concomitantly with each diet type from day 1 until the termination of the experimental protocol (4 weeks). HCD elicited significant elevations in serum levels of total cholesterol (TC), triglycerides (TGs), and high- and low-density lipoprotein cholesterol (HDL-C and LDL-C, respectively) compared with control rabbits. Moreover, aortic levels of nitric oxide metabolites (NOx) and antioxidant enzyme activities were significantly lower, while aortic levels of malondialdehyde (MDA) and myeloperoxidase (MPO) activity were significantly higher, in HCD-fed rabbits relative to control animals. CIN administration mitigated or completely reversed HCD-induced metabolic alterations, vascular oxidative stress, and inflammation. Moreover, CIN ameliorated HCD-induced vascular functional and structural irregularities. Aortic rings from HCD-CIN group showed improved relaxation to acetylcholine compared to aortas from HCD group. Moreover, CIN decreased atherosclerotic lipid deposition and intima/media (I/M) ratio of HCD aortas. CIN-mediated effects might be related to its ability to attenuate the elevated aortic mRNA expression of cholesteryl ester transfer protein (CETP) and MPO in HCD group. Interestingly, the vasculoprotective effects of CIN treatment in the current study do not seem to be mediated via Nrf2-dependent mechanisms. In conclusion, CIN may mitigate the development of atherosclerosis in hypercholestrolemic rabbits via cholesterol-lowering, antiinflammatory and antioxidant activities.

Effects of Flaxseed Oil on Serum Lipids and Atherosclerosis in Hypercholesterolemic Rabbits

Objective: Flaxseed oil has very high content of ox-linolenic acid (C18:3n-3, omega-3 [n-3] fatty acid). Based on the usefulness of n-3 fatty acid in fish oil against cardiovascular diseases, flaxseed oil is marketed as a health food. The n-3 fatty acid in flaxseed oil is different than that of fish oil. Indirect evidence suggests that the omega-3 fatty acid in flaxseed oil is not effective in lowering serum lipids and hypercholesterolemic atherosclerosis. The effects of flaxseed oil on serum lipids and hypercholesterolemic atherosclerosis are not known. An investigation, therefore, was made of flaxseed oil on high-cholesterol diet-induced atherosclerosis, serum lipids (triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, risk ratio of total cholesterol to high-density lipoprotein cholesterol), serum and aortic malondialdehyde, an index of levels of reactive oxygen species, aortic chemiluminescence (a measure of antioxidant reserve), and reactive oxygen species-producing activity of white blood cell chemiluminescence in rabbits.

Methods: The rabbits were assigned to four groups: Group I, regular diet (control); Group II, 5% flaxseed oil in regular diet; Group III, 0.5% cholesterol diet; Group IV, diet containing 0.5% cholesterol and 5% flaxseed oil. Blood samples were collected before and after 4 and 8 weeks of experimental diets for measurement of serum lipids, serum malondialdehyde, and white blood cell chemiluminescence. At the end of 8 weeks of the experimental diet, aortas were removed for measurement of atherosclerotic plaques, aortic malondialdehyde, and antioxidant reserve.

Results: Serum total cholesterol, triglycerides, and low-density and high-density lipoprotein cholesterol, and risk ratio of total cholesterol to high-density lipoprotein cholesterol, were elevated to a similar extent in Groups III and IV compared to Groups I and II. The extent of atherosclerosis in Groups III and IV was similar (56.74% ± 11.14% vs 58.01% ± 10.95%). Groups III and IV both had similar increases in serum and aortic malondialdehyde and antioxidant reserve. Reactive oxygen species-producing activity of white blood cells increased in Group III, and flaxseed oil prevented the cholesterol-induced increase in white blood cell chemiluminescence in Group IV.

Conclusion: These results suggest that flaxseed oil does not produce an alteration in serum lipids or in the extent of hypercholesterolemic atherosclerosis; however, it decreases white blood cell chemiluminescence. The ineffectiveness of flaxseed oil was associated with its ineffectiveness in altering the levels of oxidative stress.

Sulforaphane attenuates the development of atherosclerosis and improves endothelial dysfunction in hypercholesterolemic rabbits

The aim of the present work was to explore possible protective effects of sulforaphane (SFN) against atherosclerosis development and endothelial dysfunction in hypercholesterolemic rabbits. Rabbits were assigned to three groups of five: group I fed normal chow diet for four weeks, group II fed 1% high cholesterol diet (HCD) and group III fed HCD + SFN (0.25 mg/kg/day). Blood samples were collected for measurement of serum triglycerides (TGs), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), lactate dehydrogenase (LDH) and C-reactive protein (CRP). Aortic malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and total nitrite/nitrate (NOx) were measured. Vascular reactivity and intima/media (I/M) ratio were analyzed. Nuclear factor-kappa B (NF-κB) activation in aortic endothelial cells was identified immunohistochemically. HCD induced significant increases in serum TGs, TC, LDL-C, LDH, and CRP, and aortic MDA and SOD. Moreover, HCD caused significant reductions in serum HDL-C, aortic GSH and NOx. SFN administration significantly decreased HCD-induced elevations in serum TC, LDL-C, CRP, and LDH. while significantly increased HDL-C and GSH levels and normalized aortic SOD and NOx. Additionally, SFN significantly improved rabbit aortic endothelium-dependent relaxation to acetylcholine. Moreover, SFN significantly reduced the elevation in I/M ratio. This effect was confirmed by aortic histopathologic examination. The expression of NF-κB in aortic tissue showed a marked reduction upon treatment with SFN. In conclusion, this study reveals that SFN has the ability to ameliorate HCD-induced atherosclerotic lesions progression and vascular dysfunction, possibly via its lipid-lowering and antioxidant effects and suppression of NF-κB-mediated inflammation.

Biological and therapeutic activities, and anticancer properties of curcumin

Curcumin (diferuloylmethane) is a polyphenol derived from the Curcuma longa plant. Curcumin has been used extensively in Ayurvedic medicine, as it is nontoxic and exhibits a variety of therapeutic properties, including antioxidant, analgesic, anti-inflammatory and antiseptic activities. Recently, certain studies have indicated that curcumin may exert anticancer effects in a variety of biological pathways involved in mutagenesis, apoptosis, tumorigenesis, cell cycle regulation and metastasis. The present study reviewed previous studies in the literature, which support the therapeutic activity of curcumin in cancer. In addition, the present study elucidated a number of the challenges concerning the use of curcumin as an adjuvant chemotherapeutic agent. All the studies reviewed herein suggest that curcumin is able to exert anti-inflammatory, antiplatelet, antioxidative, hepatoprotective and antitumor activities, particularly against cancers of the liver, skin, pancreas, prostate, ovary, lung and head neck, as well as having a positive effect in the treatment of arthritis.

Pathophysiology and Medical Treatment of Carotid Artery Stenosis

Stroke is the third leading cause of mortality. Approximately 80 to 85% strokes are ischemic due to carotid artery stenosis (CAS). The prevalence of significant CAS is 7% in women and 9% in men. Severe asymptomatic CAS varies from 0 to 3.1%. Prevalence of symptomatic CAS is high in patients with peripheral arterial disease. CAS is due to atherosclerosis, the major risk factors for which include dyslipidemia, hypertension, diabetes, obesity, cigarette smoking, advanced glycation end products (AGEs) and its receptors (RAGE, soluble RAGE [sRAGE]), lack of exercise and C-reactive protein (CRP). This article discusses the basic mechanism of atherosclerosis and the mechanisms by which these risk factors induce atherosclerosis. The role of AGEs and its receptors in the development and progression of CAS has been discussed in detail. Lifestyle changes and medical treatment of CAS such as lifestyle changes, lipid-lowering agents, antihypertensive agents, antidiabetic drugs, anti-AGE therapy, measures to elevate soluble receptors of AGE (sRAGE, esRAGE). CRP-lowering agents have been discussed in detail. The drugs especially lipid-lowering agents, and antihypertensive and antidiabetic drugs suppress, regress, and slow the progression of CAS. The possible role of lowering the levels of AGEs and raising the levels of sRAGE in the treatment of CAS has been proposed. Lifestyle changes besides medical treatment have been stressed. Lifestyle changes and medical treatment not only would slow the progression of CAS but would also regress the CAS.

Oxidative stress as a mechanism of added sugar-induced cardiovascular disease

Added sugars comprising of table sugar, brown sugar, corn syrup, maple syrup, honey, molasses, and other sweeteners in the prepared processed foods and beverages have been implicated in the pathophysiology of cardiovascular diseases. This article deals with the reactive oxygen species (ROS) as a mechanism of sugar-induced cardiovascular diseases. There is an association between the consumption of high levels of serum glucose with cardiovascular diseases. Various sources of sugar-induced generation of ROS, including mitochondria, nicotinamide adenine dinucleotide phosphate-oxidase, advanced glycation end products, insulin, and uric acid have been discussed. The mechanism by which ROS induce the development of atherosclerosis, hypertension, peripheral vascular disease, coronary artery disease, cardiomyopathy, heart failure, and cardiac arrhythmias have been discussed in detail. In conclusion, the data suggest that added sugars induce atherosclerosis, hypertension, peripheral vascular disease, coronary artery disease, cardiomyopathy, heart failure, and cardiac arrhythmias and that these effects of added sugars are mediated through ROS.

Insights into the antiatherogenic molecular mechanisms of andrographolide against Porphyromonas gingivalis-induced atherosclerosis in rabbits

Atherosclerosis is the commonest and most important vascular disease. Andrographolide (AND) is the main bioactive component of the medicinal plant Andrographis paniculata and is used in traditional medicine. This study was aimed to evaluate the antiatherogenic effect of AND against atherosclerosis induced by Porphyromonas gingivalis in White New Zealand rabbits. Thirty rabbits were divided into five groups as follows: G1, normal group; G2-5, were orally challenged with P. gingivalis five times a week over 12 weeks; G2, atherogenic control group; G3, standard group treated with atorvastatin (AV) 5 mg/kg; and G4 and G5, treatment groups treated with AND 10 and 20 mg/kg, respectively over 12 weeks. Serums were subjected to antioxidant enzymatic and anti-inflammatory activities, and the aorta was subjected to histological analyses. Groups treated with AND showed a significant reversal of liver and renal biochemical changes, compared with the atherogenic control group. In the same groups, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total glutathione (GSH) levels in serum were significantly increased (P < 0.05), and lipid peroxidation (malondialdehyde (MDA)) levels were significantly decreased (P < 0.05), respectively. Furthermore, treated groups with AV and AND showed significant decrease in the level of VCAM-1 and ICAM-1 compared with the atherogenic control group. In aortic homogenate, the level of nitrotyrosine was significantly increased, while the level of MCP1 was significantly decreased in AV and AND groups compared with the atherogenic control group. In addition, staining the aorta with Sudan IV showed a reduction in intimal thickening plaque in AV and AND groups compared with the atherogenic control group. AND has showed an antiatherogenic property as well as the capability to reduce lipid, liver, and kidney biomarkers in atherogenic serum that prevents atherosclerosis complications caused by P. gingivalis.

Different responses of fluvastatin to cholesterol-induced oxidative modifications in rabbits: evidence for preventive effect against DNA damage

Hypercholesterolemia is a major risk factor for atherosclerosis and related occlusive vascular diseases. We investigated the effect of low-dose fluvastatin (2 mg kg(-1) day(-1)) on antioxidant enzyme activities [superoxide dismutase (SOD), catalase], vascular reactivity changes and oxidatively induced DNA damage in early stage of atherosclerosis in hypercholesterolemic rabbits. The animals were divided into three groups each composed of 10 rabbits. The control group received a regular rabbit chow diet, and the cholesterol group had hypercholesterolemic diet (2%, 4 weeks). The fluvastatin group was given hypercholesterolemic diet plus fluvastatin. Dietary intake of cholesterol significantly increased total cholesterol levels in rabbits (control, 0.85 ± 0.29; cholesterol, 12.04 ± 4.61; fluvastatin, 8.07 ± 2.72 mmol l(-1)). Hypercholesterolemic diet revealed discernible fatty streaks in arcus aortae. Fluvastatin significantly reduced the areas of the lesions. The diet significantly increased SOD activities in both erythrocyte and tissue. Treatment with fluvastatin normalized the increased activity of SOD in both erythrocyte and aortic tissues from the cholesterol group. Cholesterol feeding decreased the sensitivity to acetylcholine, and treatment with fluvastatin significantly restored the diminished sensitivity to acetylcholine in thoracic aortae. Cholesterol feeding caused oxidatively induced DNA damage in liver tissues determined by the increased levels of 8-hydroxyguanine (8-OH-Gua) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua). Fluvastatin decreased only FapyGua level in liver. In conclusion, our results may suggest that fluvastatin seems to play a protective role on high cholesterol-induced oxidative stress and DNA damage.

Low-Dose Fluvastatin Prevents the Functional Alterations of Endothelium Induced by Short-Term Cholesterol Feeding in Rabbit Carotid Artery

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, are the medical treatment of choice for hypercholesterolemia. In addition to lowering serum-cholesterol levels, statins appear to promote pleiotropic effects that are independent of changes in serum cholesterol. In this study, we investigated the effects of low-dose fluvastatin on antioxidant enzyme activities (superoxide dismutase, SOD; catalase), total nitrite/nitrate levels, and vascular reactivity in 2% cholesterol-fed rabbits. This diet did not generate any fatty streak lesions on carotid artery wall. However, SOD activity significantly increased with cholesterol feeding whereas the catalase activities decreased. The levels of nitrite/nitrate, stable products of NO degradation, diminished. Moreover, dietary cholesterol reduced vascular responses to acetylcholine, but contractions to serotonin were augmented. Fluvastatin treatment abrogated the cholesterol-induced increase in SOD, increased the levels of nitric oxide metabolites in tissue, and restored both the impaired vascular responses to acetylcholine and the augmented contractile responses to serotonin without affecting plasma-cholesterol levels. Phenylephrine contractions and nitroglycerine vasodilatations did not change in all groups. This study indicated that fluvastatin treatment performed early enough to improve impaired vascular responses may delay cardiovascular complications associated with several cardiovascular diseases.

Alternative perspectives: how chinese medicine understands hypercholesterolemia

Treatment of cardiovascular disease, albeit under the auspices of other clinical descriptors to those described in western biomedicine, has a long history in China. Chinese Medicine (CM) is guided by unique philosophical underpinnings and theories. There are differences in how the heart is conceptualised traditionally in CM compared to biomedicine. This paper focusses on how hypercholesterolemia is understood from within the Chinese medical paradigm, including its aetiology, pathogenesis, and treatment. A brief overview of the key characteristics and theories of CM is given to provide context. Modern science has demonstrated that many Chinese herbs have cholesterol-lowering properties. Examples of research into individual herbs and medicinal formulae, combinations of herbs are presented. At a more sophisticated level, some researchers are challenging some of the very assumptions upon which CM is based, including applicability of CM theory to modern clinical entities such as hypercholesterolemia, and are seeking intersections of knowledge between CM and biomedicine that may extend CM theory.

Curcumin inhibits proliferation, invasion, angiogenesis and metastasis of different cancers through interaction with multiple cell signaling proteins

Because most cancers are caused by dysregulation of as many as 500 different genes, agents that target multiple gene products are needed for prevention and treatment of cancer. Curcumin, a yellow coloring agent in turmeric, has been shown to interact with a wide variety of proteins and modify their expression and activity. These include inflammatory cytokines and enzymes, transcription factors, and gene products linked with cell survival, proliferation, invasion, and angiogenesis. Curcumin has been found to inhibit the proliferation of various tumor cells in culture, prevents carcinogen-induced cancers in rodents, and inhibits the growth of human tumors in xenotransplant or orthotransplant animal models either alone or in combination with chemotherapeutic agents or radiation. Several phase I and phase II clinical trials indicate that curcumin is quite safe and may exhibit therapeutic efficacy. These aspects of curcumin are discussed further in detail in this review.

Hypocholesterolemic and antiatherosclerotic effect of flax lignan complex isolated from flaxseed

Hypercholesterolemia, low HDL-C and oxygen radicals have been implicated in the development of atherosclerosis. Lignan complex isolated from flaxseed contains secoisolariciresinol diglucoside (SDG), 3-hydroxy-3methylglutaric acid (HMGA) and cinnamic acids. SDG and cinnamic acids are antioxidants, and HMGA is a hypocholesterolemic agent. Antioxidants are known to reduce hypercholesterolemic atherosclerosis. The objectives of this study were to determine if lignan complex reduces (i) serum cholesterol, (ii) oxidative stress, and (iii) atherosclerosis in hypercholesterolemic rabbits. Rabbits were assigned to four groups: Group I, control; Group II, lignan complex control (lignan complex, 40 mg/kg body weight daily orally); Group III, 0.5% cholesterol; Group IV, 0.5% cholesterol diet+lignan complex, (40 mg/kg body weight daily orally). Blood samples were collected before (time 0) and after 1 and 2 months of experimental diets for measurement of serum triglycerides (TG), total cholesterol (TC), LDL-C, HDL-C and serum malondialdehyde (MDA), a lipid peroxidation product. At the end of the protocol, the aorta was removed for measurement of atherosclerotic plaques, MDA and aortic tissue chemiluminescence (Aortic CL), a marker of antioxidant reserve. Rabbits in Group III developed atherosclerosis (50.84+/-6.23% of the intimal surface of the aorta was covered with atherosclerotic changes) which was associated with an increase in the serum TG, TC, LDL-C, HDL-C, MDA and aortic MDA and antioxidant reserve. Lignan complex reduced the development of atherosclerosis by 34.37% and this was associated with a decrease in serum TC by 20%, LDL-C by 14%, TC/HDL-C by 34%, serum MDA by 35% and aortic MDA by 58%. Serum HDL-C was elevated by 30% in hypercholesterolemic rabbits and by 25% in normocholesterolemic rabbits with lignan complex. Lignan complex did not affect the TC and LDL-C and serum MDA in the normocholesterolemic rabbits. However, it increased the aortic MDA in the normocholesterolemic rabbits. These results suggest that lignan complex isolated from flaxseed reduced the extent of hypercholesterolemic atherosclerosis and this effect was associated with marked decreases in oxidative stress, serum total cholesterol, LDL-C and risk ratio, and elevation of serum HDL-C. Lignan complex may, therefore, be beneficial in preventing atherosclerosis, and reducing risk factors for coronary artery disease and stroke.

Cholesteryl ester transfer protein activity and atherogenic parameters in rabbits supplemented with cholesterol and garlic powder

The current study was conducted to examine the effect of garlic supplementation on CETP activity, along with its anti-atherosclerotic effect in cholesterol-fed rabbits. Rabbits were fed a 1% cholesterol diet for 12 weeks, including a 1% garlic powder supplement. The garlic-supplemented group exhibited significantly lower CETP activity than the control group during the experimental period (P < 0.05). Among the atherogenic parameters, the total cholesterol, TG, LDL-C, VLDL-C, and atherogenic index were all significantly lower in the garlic group than in the control group during the experimental period (P < 0.05), whereas the HDL-C concentration was significantly higher in the garlic group than in the control group after 12 weeks (P < 0.05). Atherosclerotic lesion area in the aorta arch was also significantly lower in the garlic group (P < 0.05). In the morphological examination, the garlic-supplemented group exhibited far fewer fat droplet deposits than the control group. Furthermore, the garlic supplement also lowered the aortic and hepatic cholesterol, and triglyceride. Accordingly, the current results suggest that garlic exerts hypocholesterolemic and/or antiatherogenic and that plasma CETP activity might be a risk marker related with atherogenesis. As such, the inhibition of CETP activity may delay the progression of atherosclerosis, thereby supporting the atherogenicity of CETP and the inhibitory activity of garlic supplementation against CETP.

Benefits, adverse effects and drug interactions of herbal therapies with cardiovascular effects

Because the use of herbal therapies in the U.S. is escalating, it is essential to be aware of clinical and adverse effects, doses and potential drug-herb interactions. A consumer poll in 1998 indicated that one-third of respondents use botanical remedies, and nearly one in five taking prescription medications also used herbs, high-dose dietary supplements or both. An estimated 15 million adults are at risk for potential adverse interactions involving prescription medications and herbs or vitamin supplements, yet most practicing physicians have little knowledge of herbal remedies or their effects. Herbal products are marketed without the proof of efficacy and safety that the Food and Drug Administration (FDA) requires of drugs. The Dietary Supplement and Health Education Act of 1994 allocates responsibility to manufacturers for ensuring safety and efficacy with no specific requirements to submit documentation. Manufacturers may state a product's physiologic effects but may not make claims for the treatment or cure of specific diseases. Consumers and practitioners have little information about product safety, contraindications, interactions or effectiveness and are reliant on manufacturers to provide accurate labeling. Recently, the growing number of foods with herbs has raised concerns at the FDA, which requires evidence that food additives are safe. Considering that the growing appeal of herbal remedies is likely to continue, physicians, particularly cardiologists, must become familiar with the available cardiovascular information on herbs. This review highlights the existing data on the efficacy, adverse effects and interactions for herbal therapies that impact on the cardiovascular system.

Antioxidant Activity of Secoisolariciresinol Diglucoside-derived Metabolites, Secoisolariciresinol, Enterodiol, and Enterolactone

Secoisolariciresinol diglucoside (SDG), an antioxidant isolated from flaxseed, is metabolized to secoisolariciresinol (SECO), enterodiol (ED), and enterolactone (EL) in the body. The effectiveness of SDG in hypercholesterolemic atherosclerosis, diabetes, and endotoxic shock could be due to these metabolites. These metabolites may have antioxidant activity. However, the antioxidant activity of these metabolites is not known. The antioxidant activity of SECO, ED, and EL was investigated using chemiluminescence (CL) of zymosan-activated polymorphonuclear leukocytes (PMNLs) [PMNL-CL]. Other antioxidants (SDG and vitamin E) were also used for comparison. SDG, SECO, ED, EL, and vitamin E, each in the concentration of 0.5, 1.0, 2.5, 5.0 and 10.0 mg/ml, produced a concentration-dependent reduction in zymosan-activated PMNL-CL. SDG, SECO, ED, EL, and vitamin E, in the concentration of 2.5 mg/ml, produced a reduction of zymosan-activated PMNL-CL by 23.8%, 91.2%, 94.2%, 81.6% and 18.7%, respectively. Activated PMNLs produce reactive oxygen species and luminol-dependent CL reflects the amount of oxygen species generated from activated PMNLs. The reduction of PMNL-CL, therefore, reflects the antioxidant activity of the compounds studied. These results suggest that the metabolites of SDG have antioxidant activity. The antioxidant activity was highest with SECO and ED and lowest with vitamin E. The antioxidant potency of SECO, ED, EL, and SDG was 4.86, 5.02, 4.35, and 1.27 respectively, as compared to vitamin E. SECO, ED and EL are respectively 3.82, 3.95, and 3.43 more potent than SDG.

Homocysteine, a Risk Factor for Cardiovascular Disease

Fasting hyperhomocysteinemia is an independent risk factor for coronary artery disease, stroke, peripheral vascular atherosclerosis, and for arterial and venous thromboembolism. The risk for cardiovascular disease with homocysteine is similar to conventional risk factors. The interaction of hyperhomocysteinemia with hypertension and smoking is strong and the combined effect is more than multiplicative. The combined effect of homocysteine and cholesterol is additive. Homocysteine produces atherosclerosis, thromboembolism, and vascular endothelial cell injury. Vascular dysfunction produced by homocysteine may be due to endothelial cell damage. Homocysteinemia-induced atherosclerosis is probably due to various factors including endothelial cell injury, inability to sustain S-nitroso-homocysteine formation because of imbalance between production of nitric oxide by dysfunctional endothelium and homocysteine, smooth muscle cell proliferation, and thromboembolism. There is strong evidence that endothelial cell injury is associated with oxidative stress produced by homocysteine. Hyperhomocysteinemia is associated with numerous conditions, including coronary disease, stroke, peripheral vascular disease (carotid artery and cerebrovascular atherosclerosis), venous thrombosis, renal disease, diabetes mellitus, and organ transplant. Folic acid, vitamin B12 and B6 have been shown to be beneficial in reducing plasma homocysteine levels. Folic acid is specifically very effective, safe and inexpensive.